Duplex compound draft gear



June 21, 1932. J. E. MUHLFLD ET AL DUPLEX COMPOUND DRAFT GEAR Filed Jan. lO, 1950 3 Sheets-Sheet June 21, .1932- J. E'. MUHLFELD ET AL 1,864,272

lj zo" DUPLEX COMPOUND DRAFT GEAR Filed Jan. l0, 1930 5 Sheets-Sheet 2 10 I' Z3 23 z2 I INVENroRs l June 21, 1932.

6 Sheets-Sheet 5 Filed Jan. 1o, 1950 INVENTORS mw 1% .\N N NN MN N .w 1m. mNmNhN QN MN NN m l l l T- ,1 1 L ,fl -|11 -1U ,Q1 v/ m m lliilil ww l :QN N |.ll.l.| b|||| N NN 1V ,QN IHM! 1 N N WY wN MN QN .2% m MN h.. mw QQ QM. WN N Patented June 21, 1932 y UNITED STATES PATENT-orties JOHN E. MUHLFELD, OF SCARSDALE, NEW YORK, AN JOSEPH GUTTERIDG-E, OF PITTSBURG, KANSASl DUPLEX COMPOUND DRAFT GEAR Application filed JanuarylO, 1930. Serial No. 419,773.

This invention relates to a duplex compound draft gear, and hasfor its general object and purpose to provide a simply constructed and efficiently functioning dra-ft '5 gear for use in connection with rail and highway vehicles, such as locomotives, cars, automobile trucks and the like.

It is also one of the important objects of the invention to provide a draft gear which will effectively absorb shocks resulting from buff and pull, which is composed of a minimum number of parts cooperatively assembled whereby there will be a minimupn of wear and wherein the possibility of fracture or bursting of the gear will be obviated.

Our new draft gear has a minimum of nonproduction weight as compared with draft gears now in general use, wherein a large y percentage ofthe weight is in the housings and, which embody parts subject to excessive wear and liability of fracture and which do not directly function for the purpose of yieldingly resisting relative movement and absorbing shock.

Our invention also has for its purpose to produce a draft gear having a duplex compound action when the gear is under compression and in which there occurs the com- V bined wedging frictional and spring compression action between relatively movable parts so that there will be a maximum of absorption of shock and jar.

It is a further object of our invention to i provide such a draft gear having both coil and elliptic springs of the laminated type which will conjointly function in both the' compression and release action of the gear. More particularly, in addition to the main Y elliptic springs, we provide primary and eo secondary sets of coil springs, all of which function simultaneously to produce resistance of the compression of the geanand said springs likewise functioning simultaneously toI restore the draft gear to normal condition iff upon release of compression.

It is a further general object of our invention to provide such 4a dra ft gear wherein the impact stresses and strains are divided over several sets of springs acting along the 5G axial line of the gear as well as at right angles thereto so as to thereby reduce the liability of the springs acquiring a permanent set with the resultant diminution in the spring capacity or travel thereof, such as occurs when a less number of springs with greater strength are employed to perform the same work.

`Wth the above and other objects in view, the invention consists in the improved duplex compound draft gear, and in the form, construction and relative arrangement of its several parts as will be hereinafter more fully described, illustrated in the accompanying drawings, and subsequently incorporated in the subjoined claims.

In the drawings, wherein We have illustrated several simple and practical embodiments of the invention, and in which similar reference characters designate corresponding parts throughout the several views,-

igure 1 is a top plan view partly in section, showing a draft gear embodyingone form of our present improvements;

Fig. 2 is a sectional view taken substantially on the line 2-2 of Fig. l;

Fig. 3 is a detail plan view of the two side pieces of the draft gear, and

Fig. 4 is a view similar to Fig. l illustrating a slightly modified form of the device.

Referring in detail to the drawings, 5 designates the two similar end pieces or members of the draft gear which are suitably secured to the center or draft sills of therailway cars or other vehicles. Each of these end pieces includes a body plate ofvrectangular form having an integral rectangular wall 6 projecting from one side thereof and forming an open sided housing for the reception of other parts of the gear to be presently described. The body plate of the member 5 is also centrally provided with a hollow boss 7 extending into this housing, and at the base thereof with an annular recess or seat 8 to receive one of the primary compression springs.

The side members 9 are each provided with upper and lower spaced walls 10 integrally connected by the longitudinally extending web 11. The intermediate or central portions 12 of these webs of the two side members are disposed in spaced parallel relation line of buff7 and pull.

When the gear is subjected to overV solid blows, thev parts 21 of the wedgev members come into end to end contact at about the same time that the shoes 26 attachedv to the ends of spring 25contactwith the body walls of the members 5.

In the release of the gear after compression, the primary, secondary and main springs, all operate or function concurrently to restore the several parts of the draft gear to normal condition. Thus, both in compression and release of the draft gear, the impact stresses and strains are effectively divided, and distributed `between the several parts. The possibility of the springs acquiring a permanent set, thus impairing their function, is obviated. It will also be noted that by reason of the interlocking connection between the ends of the side members 13 as heretofore explained, variation in the coefficient of friction between the web parts 13 of these members and the wedge blocks which .might cause one of these sidel pieces to shift or move longitudinally with respect to the other is effectually prevented.

Preferably, the end edges of the walls 6 of the end pieces 5 kare rounded or convex as indicated at 30 so that they will not c-ut or dig into the faces of the center or draft sills upon which the gear is mounted.

Another feature of advantage in our improved gear is the ease and facility Vwith which wear and lost motion may be compensated. This may be readily done without removing the side plates and the wedge blocks, by merely inserting additional leaves or plates in the main springs 25 associated with each of the side members so that the original capacity of these springs and extent of travel of the parts with which they are associated will be restored.

In Fig. 4 of the drawings, we have shown a slightly modified construction, in which at one end of the draft gear, the end piece 5 and the wedge block 16 are integrally formed in a single casting, and one set of the primary coil springs is eliminated. The draft gear will nevertheless, function in a satisfactory manner, but at the opposite end thereof where the primary spring set is used in conjunction with the separate end member and wedge blocks, provision is made for twice the length of relative movement between the end member and wedge block than is the case in the construction of Fig. 1, as will be readily noted from a comparison of the latter figure with Fig. 4 of the drawings.

IVe are aware of various prior art devices employing frictional wedging members in combination with compression springs, and more particularly, in one of these draft gears of the prior art, the compression springs resisting the action of the frctional wedging members are arranged at right angles to the This type of draft gear differs from the other well known prior art gearsin thatinstead of the blow being directly received by the housing venclosing the frictionally coacting wedging parts, it is first cushioned by the angularly arranged compression springs. IIowever,rthis latter type of gear has met with serious objections, since the center or draft sills of the under frame of the car body` or other structure to which the gear may be applied must be perforated to receive the rod which carries and compresses the springs. Also the springs or necessary accessory parts are located outside of the draft or center'sills sothat when it becomes necessary to remove the draft gear from the car for inspection, adjustment, repairs or renewals, it is necessary to first remove this rod and the springs together with the connecting parts.

In the other conventional forms of draft gears, on the contrary, the entire gear may be removed as a unit from between the draft and center sills with the coupler and the coupler yoke, without dismantling of any of the draft gear parts.

In our present invention, it will be noted that we provide a cushioning means between the wedge blocks and the side and end members, in the form of the main compression and relief springs so that we obtain the desired cushioning action in the operation of the wedge and side members and relieve the end members of the draft gear of the destructive effects of a direct shock by the insertion of the main springs betwe-en said side members and the end pieces. This results from the fact that the side members haveV contact with the central portions of the main springs, while the end members contact with the end portions of said springs. At the same time, it will be observed-that this cushioning means is a part of the draft gear proper, and is adapted to be placed in the coupler yoke for application as a unit therewith between the draft or center sills, or removed from the same .without necessitating the disconnection of any supplementary gear parts before detachment can be effected.

From the foregoing description considered in connection with the accompanying drawings, thel construction, manner of operation and several advantages of our improved dupleX compound draft gear will be clearly understood. Wev have herein illustrated' and described several practical and satisfactory embodiments of the essential features of our invention. It will however, be understood that the same are also susceptible of embodiment in various other alternative mechanical structures, and weaccordingly reserve the privilege of resorting to all such legitimate changes therein as may be fairly considered within the spirit and scope of the invention as claimed.

We claim: 1. In a spring and friction draft rigging,

the combination of two end pieces and two -wedge blocks moved by the respective end pieces, each end piece having inclined surfaces, a cushioning and relief spring interposed between the two wedge blocks, two side pieces contacting at one of their ends with one wedge block and at their other ends with the other wedge block, two main springs, one bearing against each side piece, means on the ends of each main spring having slidable frictional engagement with the inclined surfaces of said spaced end pieces and placed under compression in movement of the latter towards each other whereby, when the end l pieces are moved under compression, the main springs will be compressed by the combined movement of the wedge blocks and the end pieces, and when the end pieces are released, the wedge blocks will be separated by the cushioning and relief spring, and the main springs will be released by a combined movement of the wedge blocks and the end pieces.

Q. In a draft gear, end members each having inclined surfaces, wedge blocks movable with the end members towards each other, side membersrhaving frictional sliding engagement at their opposite end portions with the opposite sides of the respective wedge blocks to be expanded thereby, a cushioning and relief spring interposed between the wedge blocks and yieldingly urging the same to a normal position with respect to said side members, and main leaf springs having bearing engagement against the central portions of said side members and having means at their opposite ends contacting with the inclined surfaces on the respective end members, whereby upon compression movement of the latter, said main leaf springs are placed under compression by the combined eXpansion movement of the side members under the action of the wedge blocks and by the movement of said inclined surfaces of the end members.

3. ln a draft gear, end members each having inclined surfaces, a wedge block associated with each end member, primary cushioning and relief springs interposed between the ond members and the wedge blocks, a secondary cushioning and relief spring interposed between the wedge blocks, side pieces frictionally engaged at their opposite end portions against opposite sides of the respective wedge blocks, and main leaf springs bearing against the central portions of said side members and coacting at their opposite ends with the inclined surfaces of the respective end members whereby said main springs are placed under double compression at their centers and opposite ends in the combined movement of the wedge blocks and end members.

d. In a draft gear, two wedge blocks, side members having frictional sliding engagement at their opposite end portions against opposite sides of the respective wedge blocks, an end member associated with each wedge block to move the latter towards each other upon compression, each end member having inclined surfaces, a cushioning and relief spring interposed between said wedge blocks urgingthe same to normal position, and a main spring associated with each of the side members and resisting expansion thereof in the compression movement of the wedge blocks, each main spring consisting of a plurality of superimposed spring leafv laminations, and means carried by each end of each main spring coacting with one inclined friction surface on one of the end members whereby said main springs are placed under dual compression at their centers and their opposite ends in the combined compression movement of the end members and the wedge blocks relative to said side members.

5. In a draft gear, two wedge blocks, side members having frictional sliding engagement at their opposite end portions against opposite sides of the respective wedge blocks, an end member associated with each wedge block to move the latter' towards each other upon compression, each e-nd member having inclined surfaces, a cushioning and relief spring interposed between said wedge blocks urging the same to normal position, and a main spring associated with each of the side members and resisting expansion thereof in the compression movement of the wedge blocks, each main spring consisting of a plurality of superimposed spring leaf laminations, and a detachable shoe connected with each end of each main spring and said shoes respectively coacting with an inclined friction surface on one of the end members whereby said main springs are placed under dual compression at their centers and their opposite ends in the combined compression movement of the end members and the wedge blocks relative to said side members.

6. In a draft gear, the combination of a pair of longitudinal members transversely movable towards and from each other and each having inclined plane surfaces at its opposite ends, wedges cooperating with said inclined surfaces, end members for transmitting longitudinal thrust to the wedges, main springs bearing against the outer sides of said longitudinal members, and said end members including parts cooperating with means on the opposite ends of the main springs to place the said springs under compression and cushion the impact of the wedges against said inclined surfaces.

7. In a draft gear, end members each having inclined surfaces, a wedge block associated with each end member, primary cushioning and relief springs interposed between the end members and the wedge blocks, a plurality of secondary cushioning `and relief springs interposed between the wedge blocks,

side pieces rictionally engaged at their opposite end portions against opposite sides of the respective Wedge blocks, and main leaf springs bearing against the central portions hereto.

JOHN E. MUHLFELD. JOSEPH GUTTERIDGE. 

